Mining machine



March 20, 1934. F. w. voDoz 1,951,540

MINING MACHINE Original Filed Nov. 5, 1927 6 Sheets-Sheet l l| Il l Il Il f Il ll Il l Il March 20, 1934. F. w. voDoz I MINING MACHINE Original Filed Nov, 5, 1927 6 Sheets-Sheet 2 Mlllvlll 1| J NWN. l l. mm

QN kh.

QM, N 8m.

March 20, 1934. F. W. VODOZ 1,951,540

MINING MACHINE Original Filed Nov. 5, 1927 6 Sheets-Sheet 3 March 20, 1934. F W VODOZ 1,951,540

MINING MACHINE Original Filed Nov. 5, 1927 6 Sheets-Sheet 5 March 20, 1934. F. w. voDoz MINING MACHINE Original Filled Nov. 5. 1927 6 Sheets-Sheet 6 gsm.

Patented Mar. 20, 1934 UNITED STATES PATENT OFFICE MINING MACHINE Application November 5, 1927, Serial No. 231,212 Renewed October 22, 1931 30 Claims.

This invention relates to improvements in mining machines and more particularly to machines of the truck mounted type having a prou jecting kerf cutting element adjustable in varyb ing positions relative to the main frame for making various vertical or shearing cuts.

The machine of the present invention is similar in several respects to that disclosed in my prior application bearing Serial Number 153,253,

filed December 8, 1926, and especially in so far as it affords a novel trunnioned cutter head mounting disposed both forwardly and rearwardly of the transverse axis of rotation of the cutting element, while at the same time permitting a wide range of angular movements of said cutting element in its various permissible cutting operations. In the machine of the present invention however, the supporting structure for the cutting element includes a novel form of elevating and lowering mechanism especially designed for swinging the cutter arm vertically while making side or shearing cuts. Among other objects of the invention is the provision of improved gearing connections for producing the various operative movements, as will hereinafter more fully appear.

The invention Amay be best understood by reference to the accompanying drawings, in which:

Figure 1 is a side view of the machine showing the cutter bar disposed at the far side and projecting forwardly from the main frame and inclined upwardly at an angle thereto, indicating in dotted lines another permissible position of the cutter bar;

Figure 2 is a plan view of the machine shown in Figure l and also indicating in dotted lines another permissible position of the cutter arm at the opposite side of the machine;

Figure 3 is an enlarged vertical section following generally the longitudinal center line of the machine but showing the cutter arm in substantially horizontal position at one side of the frame;

Figure 4 is an enlarged horizontal section taken on line 4 4 of Figure 3;

Figure 5 is a further enlarged section taken on line 5-5 of Figure 4;

Figure 6 is a fragmentary plan View of the front portion of the frame with parts broken away to show the operating connections for the raising and lowering devices;

Figure '7 is an enlarged detail sectional View taken on line 7--7 of Figure 3; and

Figure 8 is a detailed section taken on line 8 8 of Figure 3. The main elements of the machine include a main frame 10 and a forwardly projecting cutting element ll. The machine is moved from place to place and into angular cutting positionY by suitable traction means, herein comprising a pair of continuous tread mechanisms indicated generally at 13, 13, although it is manifest that a machine of this character might also be mounted for movement on track guided truck wheels, if desired. The cutting element herein illustrated includes a cutter bar 14 which may carry an 65 endless cutter chain about its periphery in the usual manner. The cutter bar is supported at its inner end on a yoke 18 which is pivotally connected at the side of the main cutter head indicated generally at 20. This general arrangement is illustrated in Figures l to 4, inclusive,

in which it will be seen that the cutter bar and cutter head may be bodily rotated relative to the main frame on an axis extending longitudinally of the latter from a position at one side of the 7.5 frame through an arc extending` over the top of the frame to a position at the opposite side of the frame as indicated in Figure 2.

The main bearings for the cutter head 20 comprise a cylindrical neck 21 jcurnaled in a bear- '80 ing 22 formed near the front end of the main frame 10 and an auxiliary bearing member 23 connected to forwardly extending arms 24, 24, also forming a part of the cutter head and journaled in a cylindrical outboard support or ring 25 carried on a rigid frame member 26 projecting forwardly from the lower part of the main frame. These main cutter head bearings 22 and 23, together form in effect trunnions for j the cutter head disposed forwardly and rearwardly of the point of connection of the cutter arm as is broadly disclosed in my prior application hereinabove identified, with the .cutter head.

The cutter bar 14 with its support 18 is pivotally mounted in the cutter head 20 for swinging movement in a plane parallel to the axis .of rotation of the cutter head in its trunnion supports in the following manner:-

The support 18 is provided with a hub member 27 which is journaled on a projecting bearing 28 formed integral with the cutter head 20. This bearing 28 is concentric with a cutter chain drive shaft 29 which extends longitudinally therethrough as is best shown in Figure 4. The cutter arm support 18 and hub member 27 are also connected to a transverse yoke 30 which extends across the iront of the cutter head and has a second hub member 31 journaled on a bearing projection32 arranged in alignment with bearing 28 but at the opposite side of the cutter head. A rod 33 is fixed centrally of the yoke 30 and projects forwardly therefrom through the cylindrical bearing member 23. A sleeve 34 is journaled on the forward end of the rod 33 and has a pair of oppositely disposed pins 35, 35, forming pivotal connection with a pair of vertically vdisposed links 36, 36. These links are connected at their upper ends by a tie rod 37 and are pivotally secured at their lower ends on a, shaft 38 carried by a cross member 39 as' best shown in Figures 3 and 5. The crossmember 39 is made up of a plurality of parts as is best shown in Figures 2, 3, 4 and 5. A cross-member 39a serves as a bearing for the shaft 38 and has tongues 39h, 39D, on its inner surfaces to receive members 39C, 39C, which members are threaded on the threaded shafts 40, 40, while end pieces 39d, 39d, are provided to hold the members 39C, 39C, in place on the cross- 4member .394.

' ,Power .connections `are provided for positively7 swinging the .cutter bar on its pivotal bearings .28,and `32 by means of a pair of screw shafts 140,40, having threaded connection at -opposite .ends .of ,the crossmember 39. These screw memibers Ahave bearing lat their upper ends in brackets 41, 41, projecting forwardly from the cylindrical voutboard bearing support 25 and their ,lower ends in the forwardly projecting frame .member l2.6. Each of said screw members is providedatits lower end with a worm gear 42, disposed within the frame member 26 and each meshing with a centrally disposed worm 43 on horizontal shaft 44 which also has suitable bearings in the framemember 26 including an inner bearing 45 and an outer bearing 46 as best shown inFigures 3 Iand 6. Driving connections whereby` shaft 44 may be driven from the motor will .be hereinafter more fully described in connection with therdetailed description of the gearing mechanism.

'It will be observed from Figure 5 that the threads on the screw shafts 40, 40, are right and left with respect to each other so their respective worm gears 42, 42, are driven by the single worm 43 on shaft 44 and thus raise or lower the cross member l39 which in turn causes the cutter bar 14 to be swung in a yvertical plane about an axis coaxial with the cutter chain drivingshaft 29. In the form shown in Figure 1 the cutter bar is shown in full lines in its Vraised position while in Figures 3, 4 and 5 lthe Acutter bar is shown in substantially horizontal position. It will be manifest further that vertical movement ofthe cutter bar through operation of the screw shafts 40, will be precisely the same .when the entire cutter head is rotated in its trunnion bearings 22 and 23, so asto position the cutter bar at the opposite side of the frame as shown in dotted lines in Figure 2. This arrangement affords an extremely powerful means of swinging the cutter bar vertically to make a vertical or shearing cut at either side of the machine. and at the same time affording a rigid I bearing support for the cutter head in trunnions 22 and 23. l -"Referring now to the power connections for performing the various operations of the machine above'described, I provide a motor 50, preferably mounted adjacent the rear of the main frame lO'and having a driving pinion 5l meshed with a'gear 52 on a' longitudinal shaft 53. This Shaft isconnected for driving the cutter chain through lShaft 54, beveled pinion and beveled gear 56, loosely mounted on shaft 29. A clutch member is feathered on shaft 29 and has bearing in the projecting bearing 28. Said clutch member has clutch jaws 61 adapted to engage with co-operating clutch jaws 62 on the hub of beveled gear 56 so as to provide selective vdriving engagement between said gear and shaft 29. A chain sprocket 63 of the usual form is mounted on the outer end of shaft 29 in position to drive the cutter chain (not shown).

The driving connections for rotating the cutter head 20 in its trunnion bearings 22 and 23 include a pinion 65 on shaft 53 meshing with gear 66 keyed to sleeve 67 on stub shaft 68. The sleeve 67 forms a part of a planetary gear reduction 69 of the type widely used in mining machine construction, details of which need not be herein described excepting to point out a sliding clutch member 70 thereof feathered on shaft 68 and carrying clutch jaws 71 adapted in one position to engage directly at high speed with the clutch jaws v672L of sleeve 67 and in another position t0 engage low speed clutch `jaws 72, thus affording a two speed drive for the shaft 68. Said shaft eX- tends forwardly through bearing support 73 and has a beveled gear 74 at its forward end meshing with bevel gear 75 loosely mounted on transverse shaft 76. A clutch 77 is interposed between the beveled gear 75 and shaft 76. In the form shown this clutch is of the cone type controlled by suitable means, as for instance by a s hifting rod 78 extending coaxially through shaft 76 and actuated by cam 79 on controlrod 79a, as is best shown in Figure 7. A Worin 80 is turned on the shaft 76 and is meshed with worm wheel 31 secured to and concentric with theneck 21 of the cutter head `20. By manipulation of the clutch 77 it will be seen that the vcutter head can be selectively rotated at high orlowl speed through the gearing connections just described and may also be reversed by reversal of the motor 50 in the usual manner. The worm 80l and worm wheel 81 are of the self-locking type so the cutter head will be locked for cutting operations in any ponsition to which it may be rotated.

Reversible driving connections for rotating the shaft 44 associated with thev elevating screw shaft 40 ,at the front end ofthe machine are taken off shaft68 through pinions 99 and 91. The pinion 90 is meshed with gear 92 keyed on sleeve 93 which is loosely mounted on longitudinally disposed vshaft 94. The forward end o f the shaft 94 isconnected with shaft 44 by any suitable means, in the form shown a pairl of universal joints 96, 96, and an intermediate shaft 97 being utilized since shafts 94 and 44 are slightly out of alignment with each other, as shown. A sliding clutch memberv 98 is mounted on shaft 44 and is adapted to selectivelyk engage a hub portion 99 of the foremostuniversaljoint 96. Reverse connections for driving the shafts 94, 97 and 44 in the opposite direction is vafforded through `pinion9l, idler gear 1 00 and gear. 101, keyed on sleeve 102. Said sleeve is selectively connected for driving shaft 94 through sliding clutch member 103. Clutch 1nembers95 and ,103 are preferably interlocked with each` other in the usual manner so that only oneV of theinmay bein engaged position at one time.

Through the driving connections just described the screw shafts 40 may beraised or lowered at either high or low speeds controlled by the planetary'69 and in reverse directions without reversing the motor.

. Means for driving the `traction devices 13, 413,

are also provided herein consisting of a beveled pinion 105 keyed on the rear end of shaft 94 and meshed with a beveled gear 166 on transverse shaft 107 at the rear end of the machine frame. Suitable driving and control connections are provided between shaft 107 and the endless treads 13, 13, details of which need not be described herein as they form no part of the present invention.

Although I have shown and described one form in which my invention may be embodied, it Will be understood that the construction thereof and the arrangement of the various parts may be altered without departing from the spirit and scope thereof. Furthermore, I do not wish to be construed as limiting myself to the specific embodiment illustrated, excepting as it may be limited by the appended claims.

I claim as my invention:

1. In a mining machine, a main frame, a cutter head rotatably mounted relative to said main frame upon a longitudinal axis including a cutting element offset from and mounted for pivotal swinging movement in planes substantially parallel with the axis of rotation of said cutter head, supporting means for said cutter head including an outboard bearing spaced beyond the point of connection of said cutting element and said cutter head, and coacting power means carried on said main frame in advance Vof said outboard bearing and operatively connected with said cutting element for positively swinging the latter relative to said cutter head.

2. In a mining machine, a main frame, a cut ter head rotatably mounted relative to said main frame upon a longitudinal axis including a cutting element offset from and mounted for pivotal swinging movement in planes substantially parallel with the axis of rotation of said cutter head, supporting means for said cutter head including an outboard bearing spaced beyond the point of connection of said cutting element and said cutter head, and coacting power means carried on said main frame in advance of said outboard bearing and operatively connected with said cutting element and extending through said outboard bearing for positively swinging the latter relative to said cutter head.

3. In a mining machine, a main frame, a cutter head rotatably mounted relative to said main frame upon a longitudinal axis including a cutting element oset from and mounted for pivotal swinging movement in planes substantially parallel with the axis of rotation of said cutter head, supporting means for said cutter head including an outboard bearing spaced beyond the point of connection of said cutting element and said cutter head, and coacting power means including screw devices carried on said main frame in advance of said outboard bearing and operatively connected with saidfcutting element for positively swinging the latter relative to said cutter head.

4. In a mining machine, a main frame, a cutter head rotatably mounted relative to'said main frame upon a longitudinal axis including a cutting element offset from and mounted for pivotal swinging movement in planes substantially parallel with the axis of rotation of said cutter head, supporting means for said cutter head including an outboard bearing spaced beyond the pointof connection of said cutting element and said cutter head, and coacting power means including vertically disposed screw devices carried on said main frame in advance of said outboard the cutter end of said frame, and power means t interposed between said support and said cutter head intermediate the ends of the latter for feeding said cutter arm vertically in position at either side of said cutter head.

6. In a mining machine, a main frame, a cuti ter head rotatable about an axis extending longitudinally of said main frame, a cutter arm pivotally mounted on said cutter head on an axis transverse thereto and offset from said cutter head, and means for feeding said cutter arm vertically in position at either side of said cutter head comprising a support, and a screw device interposed between said support and said cutter arm at a point intermediate the ends of the latter.

'7. In a mining machine, a main frame, a cutter head rotatable about an axis extending longitudinally of said main frame, a cutter arm pivotally mounted on said cutter head on an axis transverse thereto and offset from said cutter head, and means for feeding said cutter arm vertically in position at either side of said cutter head comprising a suppo-rt, a screw deviceon said support and linkage means for connecting said screw device to said cutter arm at a point intermediate the ends of the latter.

8. In a mining machine, a main frame, a cutter head rotatable about an axis extending longitudinally of said main frame, a cutter arm pivotally mounted on said cutter head on an axis transverse thereto and offset from said cutter head, and means for feeding said cutter arm vertically in position at either side of said cutter head comprising a support, a vertical screw journaled in said support for rotary movement therein, means threaded on said screw for movement therealong and linkage means for connecting said means threaded on said screw to said cutter arm at a point intermediate its ends.

9. In a mining machine, a main frame, a cutter head rotatable about an axis extending longitudinally of said main frame, a cutter arm pivotally mounted on said cutter head on an axis transverse thereto and offset from said cutter head, and means for feeding said cutter arm vertically in position at either side of said cutter head comprising a support, a plurality of vertical screws journaled in said support for rotary movement therein, means threaded on said screws for movement therealong, and linkage means interposed between said threaded means and said cutter arm.

10. In a mining machine, a frame, a motor, cutting mechanism therefor including a sprocket, a cutter arm having a cutter chain guided for movement thereabout in an orbital path meshed with said sprocket, said cutter arm being pivotally mounted on said frame for pivotal movement about the axis of said sprocket, a support extending beyond said frame and the pivotal axis of said cutter chain sprocket, extensible power means interposed between said support and said cutter arm intermediate the ends of the latter for moving said cutter arm about its axis of pivotal connection with said frame and means for connecting said power means with said motor-for ioo pivotally moving said cutter arm at `a plurality 'of--fri'ctionally controlled speeds comprising a frictionally controlled planetary gear reduction device.

11.. In a mining machine, a main frame, a

plurality of laterally spaced continuous tread devices for supporting said main frame, a motor, selective drive connections between said motor and continuous tread devices, cutting mechanism ytherefor including a cutter arm offset from and having a cutter chain guided for orbital movement thereabout, a cutter chain drive sprocket ydisposed rearwardly of said cutter arm, means for supporting said cutter arm for vpivotal movement with respect to said main frame about the axis of said sprocket comprising a vertically disposed screw device disposed to one side of said cutter Varm forwardly of said continuous tread devices and the axis of pivotal connection of said cutter `arm to said main frame, a selective drive `connection between said motor and screw device and 'means connected with said motor for positively swinging said cutter arm about its axis of pivotal connection to said cutter head comprising extensible power transmitting means pivotally connected between said support and said cutter arm -at a point intermediate the ends of the latter.

13. In a mining machine, a main frame, a cutter head rotatable about an axis extending longitudinally of said main frame, a cutter arm offset from said cutter head and pivotally mounted on said cutter head for movement about an axis extending transversely thereof, a motor, power means connected with said motor for rotating .said cutter head about its axis of pivotal connection with said main frame, a support proljecting beyond the axis of pivotal connection of v'said cutter arm to said cutter head, and power means connected with said motor for positively swinging said cutter arm about its axis of pivotal connection to said cutter head comprising extensible power transmitting means pivotally connected between said support and said cutter arm at a point intermediate the ends of the latter.

14. In a mining machine, a main frame, a cutter head rotatable about an axis extending longitudinally of said main frame, a cutter arm oiset from said cutter head and pivotally mounted on said cutter head for movement about an axis extending transversely thereof, a motor, power means connected with said motor for rotating vsaid cutter head about its axis of pivotal connection with said main frame, a support projecting beyond the axis of pivotal connection of said cutter arm to said cutter head, and power means Aconnected with said motor for positively swinging ksaid cutter arm about its axis of pivotal connection to said cutter head when said cutter arm is in a vertical position on either side of said main frame comprising extensible power transmitting means pivotally connected between said support and said cutter arm at a point .intermediate the vends of the latter.

15. In a mining machine, a main frame, a pluralityofllaterally spaced traction devices for supporting said Ymain frame, a motor, cutting mechanism therefor including a sprocket, a cutter arm `oifsetfrom and pivotally mounted on said main (frame for movement about the axis of rotation 'of said sprocket, 'a support projecting beyond said main frame Vand traction devices andthe 'axis of pivotal connection of said cutter arm to said mainframe, and power means connected with said motor for positively swinging said cutter arm comprising a plurality of screw devices Vjournaled in said support and disposed to one side of said cutter arm and having pivotal connection withs'aid cutter arm at a Vpoint intermediate the ends ofthe latter.

16. In a mining machine, a main frame, a plurality of laterally spaced traction devices for supporting said main frame, a motor, a cutter arm offset from and mounted on said frame for pivotal movement about an axis disposed rearwardly of its rearward end, a support projecting beyond the axis of pivotal connection of said cutter arm to'said main frame, and power means connected with said motor for positively swinging said cutter arm comprising a screw device on said support and linkage means interposed between said screw device and said cutter arm.

17. In a mining machine, a mainframe, a pair of laterally spaced continuous tread devices supporting said 'main frame, a motor, cutting mechanism therefor including a sprocket, a cutter arm offset from said main frame having a cutter chain driven by said sprocket and Iguided for movement thereabout, said cutter arm being mounted on said main frame for pivotal move.- ment about the axis of said sprocket, a lsupport extending beyond said main frame and the axis of rotation of said cutter chain sprocket, means driven by said motor for driving said tread devices including a common shaft extending longitudinally of said main frame, a -drive connection from the rearward end of said shaft to said tread devices and extensible power means selectively driven from the forward end of said shaft and interposed between sai-d support andsaid cutter arm intermediate the ends of the latterv for moving said cutter arm about its axis of pivotal connection to said main frame.

18. In a mining machine, a main frame, a pair of laterally spaced continuous tread devices supporting said main frame, a motor, cutting mechanism therefor including a sprocket, a cutter ar'm offset from said main frame and having a cutter chain driven by said sprocket and guided for orbital movement thereabout, said cutter arm being pivotally mounted on said main frame for movement about the axis `of rotation of said sprocket, a support extending beyond said main frame and the axis ,ofA rotation of said cutter chain sprocket, extensible power means disposed to one side of said cutter arm and interposed between said support and said cutter arm intermediate the ends of the latter for moving said cutter arm about its axis of pivotal connection with said frame, means driven by said motor for driving said traction devices including a shaft extending longitudinally of said frame, reverse gearing ijnterposed between said motor and said shaft and Ymeans for connecting said power means with said shaft for pivotally moving said cutter arm comprising a worm on said shaft and a plurality of worm gears driven thereby. Y

19. In a mining machine, aV main framed motor, cuttingV mechanism therefor including a sprocket, a cutter arm having a cutter chain driven by said sprocket and guided for orbital movement thereabout,v said cutter arm being pivotally mounted on said frame for pivotal movement about the axis of rotation of said sprocket, a support extending beyond said frame and the axis of rotation of said cutter chain sprocket, extensible power means interposed between said support and said cutter arm intermediate the ends of the latter for movingT said cutter arm about its axis of pivotal connection with said frame, and a drive connection from said motor to said extensible power means for pivotally moving said cutter arm at a plurality of speeds in reverse directions without reversal of said motor including a shaft extending longitudinally cf said frame, reverse gearing, plural speed gear reduction mechanism interposed between said motor and shaft and a connection from the forward end of said shaft to said extensible power means including a common worm and a pair of worm gears driven thereby.

20. In a mining machine, a main frame, a motor, cutting mechanism therefor including a cutter arm offset to one side of said main frame and having a cutter chain guided for orbital movement thereabout, a cutter chain drive sprocket disposed rearwardly of said cutter arm, a support projecting forwardly from said main frame beyond the axis of pivotal connection of said cutter arm to said main frame, means for supporting said cutter arm for pivotal movement with respect thereto about the axis of said sprocket and power means connected with said motor for positively swinging said cutter arm comprising a vertically disposed extensible power transmitting means disposed to one side of said cutter arm and connected between said support and said cutter arm at a point intermediate the ends of the latter.

21. In a mining machine, a main frame, a motor, cutting mechanism therefor including a cutter arm offset to one side oi said main frame and having a cutter chain guided for orbital movement thereabout, a cutter chain drive sprocket disposed rearwardly of said cutter arm, a support projecting beyond said main frame beyond the axis of pivotal connection of said cutter arm to said main frame, means for supporting said cutter arm for pivotal movement with respect thereto about the axis of said sprocket and power means connected with said motor for positively swinging said cutter arm comprising a vertically disposed screw device disposed to one side of said support and interposed between said support and said cutter arm at a point intermediate the ends of the latter.

22. In a mining machine, a main frame, a motor, cutting mechanism therefor including a cutter arm oirset to one side of said main frame and having a cutter chain guided for orbital movement thereabout, a cutter chain drive sprocket disposed rearwardly of said cutter arm, a support projecting beyond said main frame beyond the axis of pivotal connection of said cutter arm to said main frame, means for supporting said cutter arm for pivotal movement with respect thereto about the axis of said sprocket and power means connected with said motor for positively swinging said cutter arm comprising a plurality of vertically disposed screw devices disposed to one side of said support and journaled in said support and operatively connected to said cutter arm at a point intermediate the ends of the latter.

23. In a mining machine, a main frame, a plurality of laterally spaced continuous tread devices for supporting said main frame, a motor, selective drive connections between said motor and continuous tread devices, cutting mechanism therefor including a cutter arm offset from and having a cutter chain guided for orbital movement thereabout, a cutter chain drive sprocket disposed rearwardly of said cutter arm, said cutter arm being supported for pivotal movement with respect to said main frame about the axis of rotation of said sprocket, a support projecting beyond the axis oi' pivotal connection of said cutter arm to said main frame, and means driven by said motor and interposed between said support and cutter arm for positively swinging said cutter arm comprising extensible power transmitting means disposed to one side of said cutter arm inciuding a pair oi parallel spaced vertically disposed screw devices connected between said support and said cutter arm at a point intermediate the ends of the latter.

2i. In a mining machine, a main frame, a plurality of laterally spaced continuous tread. devices for supporting said main frame, a motor, selective l drive connections between said motor and continuous tread devices, cutting mechanism therefory including a cutter arm offset from and having a cutter chain guided for orbital movement thereabout, a cutter chain drive sprocket disposed rearwardly of said cutter arm, said cutter arm being supported for pivotal movement withrespect to said main frame about the axis of rotation of said sprocket, a support projecting beyond the axis of pivotal connection of said cutter arm to said main frame, and means driven by said motor and interposed between said support and cutter arm for positively swinging said cutter arm comprising extensible power transmitting means connected between said support and said cutter arm at a point intermediate the ends of the latter including a pair of parallel spaced vertically disposed screw devices and a link disposed intermediate said screw devices and connected between said screw devices and cutter arm.

25. In a mining machine, a main frame, a plurality of laterally spaced continuous tread devices for supporting said main frame, a motor, selective drive connections between said motor and continuous tread. devices, cutting mechanism therefor including a cutter arm offset from and having a cutter chain guided for orbital movement thereabout, a cutter chain drive sprocket disposed rearwardly of said cutter arm, said cutter arm being supported for pivotal movement with respect to said main frame about the axis of rotation of said sprocket, a support projecting beyond the axis of pivotal connection of said cutter arm to said main frame, and means driven by said motor and interposed between said support and cutter arm for positively swinging said cutter arm comprising extensible power transmitting means connected between said support and said cutter arm at a point intermediate the ends of the latter including a pair of parallel spaced vertically disposed screw devices disposed forwardly of the axis of pivotal connection of said cutter arm to said main frame, a cross-member threaded on saidscrew devices and a linkage connection between said cutter arm and crossmember.

26. In a mining machine, a main frame, a motor, a cutter arm pivotally mounted on said main frame for movement about an axis disposed rearwardly of its rearward end, a support projecting beyond the axis of pivotal connection of said cutter arm to said main frame, and power means connected with said motor for positively swingingsaidcutter arm comprising a vertically extending screw device on said support and linkage means'interposed between said screw device and vsaid cutter arm.

2 7', In a mining machine, a main frame, a motor, va. cutter arm pivotally mounted onr said main Y 2,8.l In a mining machine, a main frame, a motor, a cutter arm pivotally supported on said main frame, a support member projecting forwardly beyond the axis of pivotal connection of said cutter arm to said main frame, and power means ,connected with said motor for positively swinging said cutter arm comprising a pair of parallel spaced screw devices on said support, a longitudinally extending shaft disposed between saidscrew devices and having driving connection 'with said screw devices and a geared connection between .said shaft and motor including reverse gearing.l

2 9. Ina mining machine, a main frame, a motor, a. cutter arm pivotallyv supported konr sai,dv main frame, a. support member projecting lfoi'-vv wardly beyond the'` axis of pivotal connection-of'` said cutter arm to said main frame, and power means connected with said motor for positively swinging said cutter arm comprising a pair of:

parallel spaced screw devices on said support,A a, longitudinally extending shaft disposed; between.V

saidV screw devices and having driving connection with said screw devices, and a geared connection between said shaft and motor including I reverse gearing and a plural speed gear reduction device.

30. In a mining machine, a main frame, a motor, a cutter arm pivotally supported on said Y main frame, a support member projecting forwardly beyond the axis of pivotal connection of said cutter arm to said mainframe, and power means connected with said motor for positively swinging said cutter arm comprisingva pairof parallel spaced screw devices lon said support, a longitudinally extendingshaft disposed'betweenV said screw devices and havingdriving.

connection with said screw devices, and aY geared connection between said shaft and motor including reverse gearing and a plural speed planetary geared reduction device,

FREDERICK W. VODOZ. 

